Time has a long tail too
Bevan points us to the Terry Tate commercials from Reebok. Three years ago, they were a big hit for the company. And they're still a big hit online, gaining more than 2,000,000 views across six or seven commercials. At the end of every commercial, a splash page sends you to www.reebok.com/terrytate. No need to click... it's a 404 dead page.
Once you promote a page or a feature online, it stays promoted, pretty much forever.